How to allow access from one network to another with different routing table

I have this setup
Router with OpenWrt with two interfaces
192.168.31.1 (lan)
172.16.0.1 (lan_vpn)
two connections
wan (92.168.2.11)
wireguard (wg)
lan is connected to wan
lan_vpn is connected to wireguard

All my devices connected through 192.168.31.1 with IP 192.168.31.0/24
Also my dedicated server is connected through 172.16.0.1 -> wg with IP 172.16.0.240

to allow connection from 172.16.0.240 to wg, I added these routing rules


and everything works fine, server connection to the internet through wireguard

now I want to connect from any IP 192.168.31.0/24 to 172.16.0.240 and I don't know how to do it
I've tried to add some rules but with no luck

Still need some help :confused: